Redox-Controlled Site-Specific O-Sulfation Facilitated Diversity-Oriented Chemoenzymatic Synthesis of Chondroitin Sulfates A/C/E and Chimeric Chondroitin Sulfates

The biological functions of chondroitin sulfate (CS) are strongly influenced by its sulfation pattern. However, the limited site selectivity of currently available sulfotransferases has made it challenging to access CS oligosaccharides with diverse sulfation patterns. Herein, we report a redox-controlled site-specific O-sulfation strategy for the programmable installation of CS-A, CS-C, or CS-E sequences at defined positions along chondroitin backbones, enabling the diversity-oriented synthesis of 28 structurally well-defined CS oligosaccharides with distinct sulfation sequences.